Ministers were warned that opening England's borders to allow millions of people from Europe and the USA to enter could lead to importations of Covid variants that might cause problems in unlocking domestic restrictions.Labour stated that the government's plans to recognize vaccination status in the US and Europe if all people are fully jabbed there, made the country more vulnerable to another Delta-like variant.Members of the cabinet approved the change on Wednesday. This is a move to allow Britons who have moved abroad to be reunited back home with their families and to encourage more business travel to help boost the economy.Millions of people will benefit from the US's new initiative, including all 27 EU member countries (except France which is on the amber plus for another week), Norway, Iceland, Switzerland, and the microstates Lichtenstein, Monaco and Andorra.All arriving passengers will need to be positive for the disease before they travel and again after landing in the UK. Children who are primarily from the USA and Europe can also avoid quarantine.Europeans will need their digital Covid certificate. Americans without an app will need to show the Centers for Disease Control card that they were issued when they were vaccinated.Aviation and tourism companies welcomed the news, which added nearly 2bn value to their businesses. One industry group admitted that the summer season was almost over, while another said that the US had not made a reciprocal agreement to allow them to relax restrictions on their side of the Atlantic.Scotland said it would follow suit, but kept the situation under review. Mark Drakeford, the first minister for Wales gave reluctant support to the change. He stated that it was difficult to not agree with the change for practical reasons, but that Westminster politicians were making decisions we wouldn't have made. He reiterated his belief that people should not travel abroad in this year's election.Jim McMahon (shadow transport secretary) criticised ministers' recklessness and demanded evidence to prove that the move wouldn't lead to another variant running wild through the country, thereby causing harm to the efforts of the British public.Alexandre Holroyd (deputy in the National Assembly) representing French citizens in northern Europe called the decision to exclude travelers from his country ridiculous, tweeting: Decisions without science or logic. Kafka is on vacation with Godot.The UK saw a rise in Covid cases, surpassing 4,000. This ended the seven-day streak that saw falling numbers which had provided ministers and their advisors with reason for optimism.The number of daily deaths in the UK fell by 40 to 91. Hospitalisations continued to grow, but at a slower pace to 6,021.Boris Johnson, the prime minister, attempted to reduce expectations by telling people to remain cautious and predicting that there will still be bumps in the road later in this year.Scientists disagreed on the threat posed by the government's decision to let more people enter the country without quarantining.Professor Christina Pagel, who is the director of UCL's clinical operational research unit, expressed concern about the possibility that people not fully vaccinated could still contract the virus and can pass it on to others.She stated that a new, worrying variant could be discovered in the US or Europe. If travel is less restricted between these places and the UK, a variant will emerge anywhere.Pagel stated: We should take advantage of our island status and have more control over any new variants that may be introduced.Sir John Bell, the regius professor in medicine at Oxford University, said to the BBC that it was selfish for the government not to focus on giving full vaccinations to people who are fully vaccinated, while people living in poorer countries do not have the option.He pressed the government to send more doses abroad and said: "If you want variants, then you have the perfect storm." This is not Watford, but in Zimbabwe, Rwanda, South Africa.Professor Ravi Gupta is a clinical microbiologist from the University of Cambridge. He said that there are more serious conditions in the UK for the development of variants that could escape vaccines. He also suggested that it would be sensible to allow fully vaccinated travelers in without quarantine given the absence of any legal restrictions.Paul Hunter, a professor of medicine at University of East Anglia, said that the UK was more of a threat to other countries than it has been to them recently. He also stated that new variants of the virus were alarming, but travel restrictions delayed their arrival.Grant Shapps (transport secretary) said that it was safe for the border to be opened. Grant Shapps, the transport secretary, announced that international cruises will soon resume. He also stated that there would be no testing for drivers entering the country who do not leave their vehicle.Joss Croft (chief executive of UKinbound) praised the great step taken to allow more fully vaccinated travelers to avoid quarantine as a way to rebuild Britain's tourism industry.Croft stated that businesses dependent on foreign tourists still face significant barriers to recovery. Other countries are reopening quicker and the US is still warning its citizens against traveling to the UK. He said that the valuable summer season 2021 is almost over and that it would put thousands of jobs and businesses at risk.The ABTA, a travel association, warned that the aviation sector was not alone in its troubles. The spokesperson for the group stated that other countries are opening faster than the UK and asked the government to include more destinations on the green list. This will be reviewed next Wednesday, with changes taking effect starting from 9 August.